Transport technology includes other related technologies used to exchange and transmit information between communication service users, such as a network structure, a switching method, transmission system, and transformation of information into the format for transport layer to equally provide an information transport service to all users of a transport network.
In case of a telephone service network transmitting speech signals between network users, the technologies applied thereto include an entire numbering system, a hierarchical network configuration, a Dual-Tone Multi-Frequency (DTMF) signaling between a user and a transport network, a CCS No. 7 Signaling within a transport network, a fixed bandwidth provided to each user based on 64 Kbps circuit switching, a transmission based on synch multiplexing, and transformation from speech analog signals into digital signals based on pulse code modulation.
Conventional transport technologies are developed to apply resources efficiently according to characteristics of a service provided to the network users. The telephone service network employs a circuit switching method that can minimize an end-to-end delay and delay shift of a speech signal which are needed for natural conversation between the network users. The Internet adopts a packet switching method to transmit data having a variable length, i.e., variable-length data, without loss and increase the utilization efficiency of network resources, and mobile telecommunications networks have called for development of signaling methods for positioning a network user and exchanging positioning information.
In the conventional transport technologies, when a system needs to accommodate a service which is different from the characteristics of a service aimed by each transport technology, the service quality which is expressed as the extent of service characteristics satisfied by the transport network cannot be fulfilled. Otherwise, to fulfill the service quality, the system should take the disadvantages that the network resources are used less efficiently and the transport technology become more complicated to fulfill the service quality.
Recently, communication services are advancing through integration between services and the concept of easy-to-use services, and researchers attempt to integrate transport technologies to jump on the trend. That is, researchers are studying to develop a transport network configuration, a switching method, a transmission system, and transformation into an information transport layer to integrate and process diverse information transport schemes with different service qualities requested by the users. When they are integrated into one transport technology, a network service provider can reduce costs for managing the network and the users can receive a service in a desired service quality without making an enrollment for each service quality.
The services provided to the users through the transport network become to have higher service qualities from speech, message and video services to integrated forms thereof. The users of the transport network request to change the service quality standards, as the services are extended into an area of machine-to-machine information transport. The service quality standards include how much of a bandwidth requested in a fold number of the minimum bandwidth from several Kbps to several Gbps can be guaranteed in end-to-end, how much information can be lost when information is transported in end-to-end, and the extents of end-to-end transport delay and inter-delay shift. The service quality requested by a user of the transport network is formed of an arbitrary combination of service quality measures, and the transport network should provide a customized service quality according to a user service.